1. Field of the Invention
The present invention relates to a threading mechanism for a magnetic recording/reproducing apparatus for taking out a leader pin secured to one end of a magnetic recording tape from a single reel cartridge, moving the lading pin to a predetermined guide path and threading the magnetic recording tape around a reel in the apparatus.
2. Description of the Related Art
In this type of threading mechanism, when a cartridge loader for holding a cartridge is moved to the cartridge loading position of a deck base by a loader guide mounted on the deck base, a leader pin is held and guided to a reel through a guide path by a threader drive.
In this case, the threading drive is designed so that leader block 16 having a hook 16-2 which is hooked to the leader pin to hold the leader pin (not shown) is guided to the guide path (not shown) by the threading pin 10 as shown in FIGS. 1 and 2. At the cartridge loading position, the hook 16-2 is hooked to the leader pin through the operation of guides (guide grooves 15-1, 15-2) of guide cam 15 and retractor block 17 which are respectively secured to the deck base (not shown).
That is, the leader block 16 has pins 16-3 and 16-4 at the upper and lower portions thereof, and they are located in the guide grooves 15-1, 15-2 and the groove 17-1 of the retractor block 17 respectively. When retractor cam 4-8 provided to the cartridge loader (not shown) abuts against the retractor pin 13-2 of the retractor block 17 when the cartridge is loaded, the retractor block 17 is rotated around the pin 2-2 serving as the support shaft thereof the against the tensile force of a retractor spring 13-3 and also the threading pin 10 is moved to the guide path side, whereby the pins 16-3, 16-4 are slid in the guide groove 15-2 and the groove 17-1. During this sliding motion of these pins, the leader block 16 is rotated while guided along the groove 15-2 and hooked to the leader pin. The pins 16-3, 16-4 are released from the guide grooves 15-1 and 17-1 by the time when the loading operation is completed, and the leader block 16 is moved to the guide path while guided by the threading pin 10.
In such a conventional threading mechanism, the leader block 16 is rotated by the rotation of the retractor block 17 and the pulling operation of the threading pin 10 to the guide path side, whereby the leader pin is hooked by the hook and clamped by the leader block 16. Therefore, a stable operation could not be achieved unless the synchronizing adjustment between the retractor block 17 and the threading pin 10 is not accurately carried out.
The present invention has an object to provide a threading mechanism for a magnetic recording/reproducing apparatus in which an operation of clamping a leader pin by a leader block is carried out by a simple rotational motion of the retractor block, thereby achieving a stable operation.
In order to attain the above object, according to the present invention, a threading mechanism for taking out a leader pin secured to one end of a magnetic recording tape from a single reel cartridge, moving the leader pin to a predetermined guide path and threading the magnetic recording tape around a reel in a magnetic recording/reproducing apparatus, comprising:
a cartridge loader for holding the cartridge;
a deck base which mounts a loader guide for moving the cartridge loader to a cartridge loading position; and
a threader drive for holding the leader pin and guiding the leader pin to the reel through the predetermined guide path when the cartridge loader is moved to the cartridge loading position;
wherein the threader drive provides a leader block having a hook which holds the leader pin, and the leader block is rotated to engage the hook with the leader pin in cooperation of a retractor cam provided to the cartridge loader and a retractor provided to the deck base.